The invention is related to an integrated semiconductor circuit comprising a control circuit, an output stage, an input and an output, the output stage comprising pull-up means connected between a first supply terminal and the output and pull-down means connected between a second supply terminal and the output, said control circuit controlling at least one of said pull-up or pull-down means for limiting the time rate of change of current at the output upon receipt of an input signal change at the input.
Such a circuit is known from a publication in I.B.M. Technical Disclosure Bulletin, Vol. 27, No. 1A June 1984, pages 13-14. In said publication the problem of package inductance generated power supply line noise (voltage bumps) has been discussed. The supply line noise will be generated when large fast current spikes occur in said supply lines. In VLSI circuits e.g. byte wide static random access memories this problem is very troublesome, in particular if eight output loads of 100 pF have to be driven from 0 Volts to +5 Volts or vice versa. It is easily to understand that a fast charge or discharge of said loads will cause a large current peak in the power supply lines thus generating noise. Large pull-up or pull-down output transistors will respectively charge or discharge the loads very fast, which is an advantage, but then so much ground noise will be generated that e.g. a false retriggering of an address input transition detector will occur.
In the above-mentioned publication a control circuit is provided for controlling the push-pull output stage of the so-called off-chip driver, in which the time rate of change of current is limited. However the shown circuit does not function satisfactorily. As described in the publication the control circuit has an output node, which is connected to the gate of a pull-down transistor and which is charged at a slow rate in the beginning and then charged at a fast rate. Due to the characteristics of the pull-down Field Effect Transistor and to spread of parameters in production process the circuit does not perform as it has been designed.